What is trefis?<p>I can't figure out where they came up with the $391B market cap number, much less why they came up with that estimate?<p>It's certainly not based on the current stock value.
We're extrapolating market capitalization into the future within a model. If we applied a similar model for the rest of the top 25 corporations by market cap on the S&P 500, we probably find that the iphone won't be worth more than all but 8 companies. This is given the model is accurate, and the pricing method is accurate of the iphone is accurate.